The forward spent three years with Trotters after joining in January 2007 from Slovakian outfit Senec, but played only for the reserve team.
Harsanyi's deal at Bolton expired this summer and the 23-year-old says he rejected the proposal of a new contract, which would have seen him continue in the reserves.
He has instead chosen to return to his native Slovakia to play for top-flight club Dunajska Streda, and the striker is set to pen a half-year deal with the option of a further six-month extension.
"Yes, that is true. I have reached an agreement with Dunajska Streda although I am yet to pen the contract," Harsanyi told SITA, the Slovak News Agency.
"After leaving Bolton I have been training with Dunajska Streda for two weeks.
"During that time all has turned out towards my move there. I had a chat with coach Radvanyi and told him I needed to play regularly. He assured me that would be the case and, as he needed a striker, the agreement was reached."
Harsanyi also revealed that several lower division English and Scottish clubs were keen to secure his signature.
"I had offers from elsewhere, too. Clubs from lower English divisions and Scottish clubs were interested in my services," he added.
"I considered all offers and eventually decided to move to Slovakia. It would not pay off to play abroad where things are not always ideal.
"Moreover, I know that at Dunajska Streda I will be playing regularly and have a good relationship with coach Radvanyi, so I am looking forward."